My Globe Vienna is the first bike with disc brakes that I have owned. My first foray into adjusting the brakes came recently when I removed my wheels to clean out my fenders. I had heard disc brakes were rather easy to adjust so I started Googling around and stumbled into several videos like the one below posted on the MTB Workshop site.
The instructions on all of the videos are rather simple:
1. Loosen the brake body.
2. Engage the brake.
3. With the brake engaged, tighten the brake body back up.
4. Enjoy a beverage of choice, filled with a sense of pride.
I performed the procedure as instructed (with my bike upside down) and spun the wheels and everything seemed to be a okay. I thought to myself, "Awesome!" and rewarded myself with a beer.
The next day on the way to work however I ran into a problem. Everything started off okay but there are a few times during my rides to work that I will stand up in my pedals and as I pedal the bike torques a bit from side to side. The first time I stood up while going up an incline, with each stroke I heard a high pitched grinding noise. It was very rhythmic and I did not need to be a rocket scientist to figure out that the front brake disc was grinding against something - and the geometric pattern of the holes cut into the disc made for a high pitched ear piercing experience.
As soon as I sat back down and rode without side torque, everything was fine. I stopped to make sure my wheel was on tight and spun it a few times and did not see any immediate danger so I just made sure to sit down the rest of my ride.
When I got to work I flipped my bike upside down and after peering around a bit I discovered what was going on. Take a look at the following:
I am not sure about all of the specific names, but what I would call a washer and a spacer on the Allen bolt holding the brake in place were extremely close to the disc - see the end of the arrow. The washer and spacer sit a little loose on the Allen bolt and when I adjusted the brake I guess the washer and spacer shifted too close for comfort to the disc. Thus, when torqued side-to-side when I stood up in my pedals the disc was brushing up against the spacer and washer, resulting in a very high pitched and annoying noise.
I do not have a lot of tools at my office, but I knew that I needed to push the spacer and washer as far away from the disc as possible. I tried a letter opener at first but it didn't do the trick, so I then moved to a cheap steak knife (portabella mushroom knife if you are a vegetarian) that ended up working out just fine, check it out -
I loosened the brake, slipped the knife into the gap to move the washer and spacer over as far as possible, held the brake lever tight, and tightened the Allen bolt. The ride home was free of noise, and my ears rejoiced. Do you have some brake adjustment hacks, feel free to pass them along for us to post.